Studies on the genetic and molecular basis for clubroot resistance in canola

The Challenge

Due to the complex pathotype structure of clubroot in Alberta, current clubroot resistant varieties have the possibility to erode or breakdown altogether. This is a response to selection pressure imposed by clubroot resistant canola as they are most likely based on a single clubroot resistant gene.

The Project

To find a rational approach to durable clubroot resistance breeding through identifying independent clubroot resistant genes and molecular markers, understanding their behavior in different genetic backgrounds, investigate the biological function of both host and pathogen throughout the infection stage, as well as evaluating feasibility of resistant gene pyramiding.

The Results

• 12 molecular markers, and a resistant locus were identified.
• Durability of clubroot resistant genes increase with longer rotations out of canola in fields with clubroot.
• Small percentage of susceptible host plants (weeds: volunteer canola, shepherd’s purse, stinkweed etc) within a clubroot resistant crop can help maintain inoculum levels, regardless of rotation length.

Grower Benefits

Identifying these molecular markers will help breeding programs increase their clubroot resistance gene package durability. Relying solely on genetics and disregarding best management practices has shown to be successful for only a short time. With increase knowledge of clubroot, a quality weed control system and increase time out of canola is required for long term management of this disease.